What’s kosher?

President Barack Obama will be eating kosher when he arrives to stay at Jerusalem's King David Hotel for a summit meeting next week, after the hotel switches to a menu designed around religious dietary restrictions ahead of the Passover holiday.

What does that mean for the president?

“Kosher” literally signifies food that is “acceptable” by Jewish dietary laws — meaning no pork, no shellfish and no mixing meat and milk. The rules come from the Bible: not eating milk and meat together stems from an admonition not to eat a kid goat boiled in its mother's milk, for example.

Passover commemorates the (also Biblical) exodus of the Jews from Egypt. Forced to flee, they were unable to allow their bread to leaven. (Bread leavening actually took days in the pre-industrial era, when commercial yeast was unavailable and a thin dough would be set out to collect naturally occurring airborne yeast until it began to rise.)

As a result, Jews do not eat leavened foods during Passover. Leavening is interpreted broadly, so, for example, pasta is also prohibited since the mixing of water and flour could theoretically result in some rising.

More from GlobalPost: UN: Palestinian rocket likely killed Gaza baby, not Israeli airstrike

Cleaning the home — or, in this case, the hotel — of all leavened goods is a huge production that lasts many days. The King David Hotel has a full house for the holiday, which starts two days after Obama's departure, and many of the guests are religiously observant Jews coming for some absolutely, totally kosher Passover sunshine and relaxation. So the hotel says it has no option but to kosherize before the president’s arrival.

So Obama won’t be getting toast for breakfast. Luckily for him, however, many of his meals will be at other locations not subject to the same strictures.